A bulldozer as a work vehicle is disclosed, for example, in Japanese Patent Laying-Open No. 2005-113674 (PTL 1). This Japanese Patent Laying-Open No. 2005-113674 discloses what is called a slant nose bulldozer in which an engine compartment surrounding an engine is arranged at a front end of a vehicle frame and an engine cooling module is arranged at a rear end of the vehicle frame, so that operator's front visibility is improved.
In addition, in order to prevent penetration of dust, water, or the like, an air pressure in an operator's compartment (a cab) (an internal pressure) of such a work vehicle as a bulldozer has been made higher than an air pressure outside the cab (an external pressure) by blowing air from an air-conditioner. A technique for thus preventing penetration of dust particle or noise from the outside by improving hermeticity in the cab is disclosed, for example, in Japanese Patent Laying-Open No. 2001-81811 (PTL 2).
In Japanese Patent Laying-Open No. 2001-81811, a cab is formed by fitting a floor frame to a cab main body having an opening in a bottom portion and a gap between the cab main body and the floor frame is sealed. Here, a sealing member is either interposed between upper and lower joint surfaces of a mount portion on a cab main body side and the floor frame or arranged between an outer peripheral portion of the floor frame and an inner peripheral portion on the cab main body side opposed thereto.